Response:
With a monthly expense of $20,000, Ricardo can make 25 trips via metro and 16 trips by bus. If he undertakes 21 trips weekly, that amount is insufficient to cover bus fares.
Overview:
The problem can be resolved by dividing the weekly expense of $20,000 by the cost of the two forms of transportation: $800 (metro) and $1200 (bus). Knowing he makes 21 trips, the result must meet or exceed that to confirm that Ricardo can accommodate his weekly travel needs. In this instance, he can fulfill the requirement using the metro (with spare funds remaining), but not with the bus (he will be short on funds).
